For the second day in a row, Delhiites on Wednesday faced toxic levels of pollution, forcing the government to shut schools for the rest of the week, stop the entry of trucks carrying non-essential goods and ban construction.

On Tuesday, the Air Quality Index of the Central Pollution Control Board (CPCB) had hit 'severe' for the first time this season, with a value of 448.

Wednesday saw the AQI increase to 478.

Apart from Delhi, neighbouring Faridabad, Ghaziabad, Gurugram and Noida were also in the ‘severe’ category.

According to the CPCB, the still conditions on the ground coupled with winds bringing pollutants from crop burning as well as moisture from neighbouring States had led to the dense haze settling on the National Capital Region.

The smog persisted through the day, bringing a fall in maximum and minimum temperatures. High humidity and low wind speed continued to create conditions favourable for fog.

The India Meteorological Department issued a warning for dense to very dense fog on Thursday and Friday in the morning over Delhi, Punjab, Haryana, western Uttar Pradesh and north Rajasthan.

Truck mows down nine

The cover of smog over the region led to accidents, with nine persons killed when a truck mowed them down on the Bathinda-Chandigarh highway and four people injured in a car pile-up on the Yamuna Expressway near Greater Noida.

On Wednesday evening, Delhi Lieutenant-Governor Anil Baijal chaired an emergency meeting with Chief Minister Arvind Kejriwal. Mr. Baijal said the entry of commercial goods carriers, apart from those carrying essential goods, was banned; civil construction would be banned to prevent dust pollution; all schools would be closed this week; parking charges would be hiked; and the frequency of buses and Delhi Metro trains increased to encourage the use of public transport.

The Union Health Ministry issued an advisory instructing people to remain indoors if they have breathing difficulty, to try keeping children indoors as much as possible and to go to a hospital in case of any complications. Delhiites were also advised to avoid morning walks or any other strenuous outdoor activity and smoking.

All India Institute of Medical Sciences Director Randeep Guleria warned that N95 masks and air purifiers may not provide full-time protection from respiratory threats during the current conditions.

“Once again, I want to warn that patients may die due to the current pollution levels, especially the ones who have respiratory issues. This is a silent killer. The most affected are children and the aged,” he said, adding that children could face serious implications in the next 20 years as their lungs are being affected today.